class Point {
    int x,y;
    void setXY(int m,int n){
      x=m;
      y=n;
    }
}
public class Example4_4 {
    public static void main(String args[]) {
    Point p1,p2;
    p1 = new Point();
    p2 = new Point();
    System.out.println("p1的引用:"+p1);
    System.out.println("p2的引用:"+p2);
    p1.setXY(1111,2222);
    p2.setXY(-100,-200);
    System.out.println("p1的x,y坐标:"+p1.x+","+p1.y);
    System.out.println("p2的x,y坐标:"+p2.x+","+p2.y);
    p1=p2;
    System.out.println("将p2的引用赋给p1后:");
    System.out.println("p1的引用:"+p1);
    System.out.println("p2的引用:"+p2);
    System.out.println("p1的x,y坐标:"+p1.x+","+p1.y);
    System.out.println("p2的x,y坐标:"+p2.x+","+p2.y);
    }
}


